<!DOCTYPE html>
<title>CSS Anchor Positioning: try-tactic (margin)</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#typedef-position-try-fallbacks-try-tactic">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
  @position-try --pf {
    left:10px;
    top:20px;
    margin: 5px 15px 25px 35px;
  }
  #cb {
    position: absolute;
    width: 400px;
    height: 400px;
    border: 1px solid black;
  }
  #target {
    position: absolute;
    left: 99999px; /* force fallback */
    width: 30px;
    height: 40px;
    background-color: skyblue;
  }
</style>
<div id=cb>
  <div id=target></div>
</div>
<script>
  function test_try_tactic(try_tactic, expected_offsets) {
    target.style.positionTryFallbacks = `--pf ${try_tactic}`;
    test(() => {
      assert_equals(target.offsetLeft, expected_offsets.left, 'offsetLeft');
      assert_equals(target.offsetTop, expected_offsets.top, 'offsetTop');
      assert_equals(target.offsetWidth, expected_offsets.width, 'offsetWidth');
      assert_equals(target.offsetHeight, expected_offsets.height, 'offsetHeight');
    }, target.style.positionTryFallbacks);
  }

  let w = 30;
  let h = 40;
  let cbw = 400;
  let cbh = 400;

  test_try_tactic('', {left:10+35, top:20+5, width:w, height:h});
  test_try_tactic('flip-block', {left:10+35, top:cbh-h-20-5, width:w, height:h});
  test_try_tactic('flip-inline', {left:cbw-w-10-35, top:20+5, width:w, height:h});
  test_try_tactic('flip-block flip-inline', {left:cbw-w-10-35, top:cbh-h-20-5, width:w, height:h});
  test_try_tactic('flip-start', {left:20+5, top:10+35, width:h, height:w});
  test_try_tactic('flip-block flip-start', {left:cbh-h-20-5, top:10+35, width:h, height:w});
  test_try_tactic('flip-inline flip-start', {left:20+5, top:cbw-w-10-35, width:h, height:w});
  test_try_tactic('flip-block flip-inline flip-start', {left:cbh-h-20-5, top:cbw-w-10-35, width:h, height:w});
</script>
